Production of light with a portable light source or flashlight is a well known expedient in which a tubular body is fitted with a number of series connected batteries. The disadvantages of conventional flashlights with this conventional configuration are generally (1) breach of internal external integrity from having to access the battery compartment fairly regularly to replace batteries, and (2) other breaches of external integrity associated with light bulb changes at the front of the device and from a mechanical linkage relating to the on and off switch.
In some devices especially built for underwater use, a series of multiple “o” rings may be employed for water sealing. However, when these structures are employed at points likely to be repeatedly accessed, such as the rear entrance to the battery compartment, degradation will likely occur resulting in an eventual breach of sealing integrity.
Other step have been taken to insure integrity such as placing a flexible push button cover over the on and off switch, but these covers tend to either leak early in their functional life at the ring of circular attachment, or later in their functional life by cracking or punching breach. Seals around the bulb changing entrance, typically the front lens cover have proven to be more secure.
Production of energy for lighting using generator devices are also known. In some cases a crank generator is provided with the crank extending through the housing, creating another source of housing fluid breach. Either a scientifically closely toleranced bearing must be provided to keep moisture out (close tolerance along with friction loss) or the generator must itself be water proof. The generator is itself a complex mechanical machine and also prone to water damage, rust, and excessive wear.
Because of the breakdowns cited above, non-battery flashlights are generally unreliable as an emergency or long storage time period source of lighting, and particularly in a harsh or moist environment.
Further, the majority of personal lighting products are generally inefficient as being operated using an incandescent (heated filament) light source which is not conserving of energy usage per unit of illumination. Most generator models require considerable hand crank input to effect any significant light output over time.
What is therefore needed is a more compact, more isolated source of emergency lighting which is human powered, but which is also efficient in operation. The device should be impact resistant and have relatively few moving parts and no intense, high force, small area wear surfaces.